


Bond Compatibility

by Fangirl_Goon_Squad



Category: Captain America (Movies)
Genre: AU-Pre-Civil War, Alpha Steve, Bond Compatibility, Cameos By Mention, Deprivation Disorder, Hiding From Biology Doesn't Work, Knotting, Language Captain, M/M, Omega Bucky/Winter Soldier, Priorities, Rut, Smut, Steve's Had It With Everybody's Everything, Stucky - Freeform, These Jerks Are NOT Politically Correct, Weirdos In The Woods, a/b/o dynamics, heat - Freeform
Language: English
Status: In-Progress
Published: 2017-06-13
Updated: 2017-06-13
Packaged: 2018-11-13 16:34:31
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 4
Words: 6,884
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11189058
Author URL: https://archiveofourown.org/users/Fangirl_Goon_Squad/pseuds/Fangirl_Goon_Squad
Summary: I think this may be my shortest finished attempted fic so far.  Steve is marginally still working with Shield, although in the wake of the events of The Winter Soldier his ties to military and governmental work have been wearing thin very quickly and most agencies no longer actually trust him unless it's in an active combat situation.IF YOU DO NOT GET ON WELL WITH THE A/B/O CONCEPT, THIS IS NOT THE FIC FOR YOU.





	1. Chapter 1

**Author's Note:**

> So most of my personal AFK issues are dealt with, but I'm still working off a heckuva year thus far. I felt like writing something with "this is not your Cap speaking" Steve Rogers. I find the A/B/O dynamics interesting (might have to do with I've been watching wildlife documentaries since about 1973) and although I have a much, much longer fic in the works about A/B/O stuff, it still needs a bit more gratuitous violence to pass muster with me. Still, I've finally sorted out what's PMS, what's the foul mood thunderous weather always puts me in (imminent rain makes my arthritic hands hurt just fiercely), and what's just me having had enough of this damn year already. I tried to be sure only "enough of this damn year" was the only irritable energy I put in on this one.
> 
> I'm pretty sure part of that energy is 'you haven't published anything in weeks, you lazy writer you", which is a part that tends to ignore the other stresses in my life.
> 
> In case I break the chapter counter AGAIN, this one should have 4 chapters.

“Captain Rogers?” An unwelcome voice interrupted his evening jog; he'd only answered after recognizing the incoming number to have a chance to snarl at his caller.

“I'm **not** coming in, Natasha. Not for you, not for Fury, not for anyone.”

“You're right, not for me. And this isn't about turning yourself or anyone else in. No agencies involved. We have a much bigger problem here.”

“Where are you and what's important enough for you to risk calling me?” Things had gotten a lot easier with Sam Wilson, but Romanoff remained firmly on his shit list and few of the other Shield agents or Avengers ever tried to deal with him any more. He'd been clear enough during his 'exit interview', which had consisted of him throwing all his issued gear except for two items onto Fury's desk and just walking away. All other thoughts fell away when he heard a bellow surge amid the background noise of her call. The hair on his forearms and the nape of his neck rose uncomfortably at his certainty that he knew that voice. Romanoff knew he would, and did not use his name since this wasn't necessarily a secure line.

“We brought him to Lehigh. There's more than one secret bunker under your old stomping grounds, Cap. He needs your help.”

“You... _unbelievable_ fucking **bitch**!” Rogers exploded in a hiss of rage. “Whose idea was it to hurt him to try to bait me in? I'll kill every _fucking_ one of you, I swear to—”

“Steve, shut the fuck up. Lehigh isn't active with anyone, not Hydra, not Shield, and not any branch of the Armed Services. That's why we chose it! We could have him three hundred feet under a mountain in Utah **hoping** everyone there was still Shield, but we never called anyone but you. And those noises are not our fault—there's no one in there with him and for damn good reason. _We're_ not hurting him, but he is in pain and in trouble. He needs **you** , for Christ's sake, Steve! Do you think I'd call you if we had any other options?” Another roar, this one with edges of a shriek trying to break through, subsumed other background noise. Having Captain America snarling profanity in her ear had distracted her from the display that was relaying the sounds of such distress.

Steve Rogers threw his Shield-issued cell into a fountain with the call still open, bolting for his apartment and grateful the vibranium shield was still where he'd hidden it along with the only gun he'd ever really felt comfortable with, his original service-issue pistol. Those were the only two items he'd kept—the gun and the shield itself. Even with his augmented night vision letting him run his motorcycle dark and well over a lot of speed limits, it seemed to take _forever_ to get to New Jersey.

Where he was met at the gate by a nervous young Beta who wasn't happy about accepting the brusque invitation to get on the passenger seat of the Harley if he wanted to be back in time to report anything to anyone. Fortunately, the building that slid a door open for the bike was not far from the main gate. The lab tech—by now, he knew them in or out of sterile gear—was still nervous as he used cards and codes to get them to the last level in the place.

Rogers was met by Natasha. And a wave of brain-bending scent that actually made him reel back into the wall. There wasn't any screaming but that was because they'd finally gotten enough tranquilizer darts into the Winter Soldier, who was collapsed in a heap in a windowless cell, visible at the moment only by camera.

“What. The. **Fuck**. Natasha?”

“Did you know before the war?”

“Know what?”

“That _smell_ , Steve. You're an Alpha, medically confirmed beyond all doubt, so you know exactly what that is. You can't tell me it's not working your nerves as hard as it is mine, because I'm as Alpha as you are. I'd have dealt with this myself but he...declined my offer to help.” Specifically, he'd told the camera that if he saw 'that redheaded Russian bitch' again he'd do his best to disembowel her if he had to do it with his teeth. Given that he'd already shot her twice in the last decade without even recognizing her, she was disinclined to test his vicious temper.

“Bucky's a _Beta_. He never presented heat or rut, and never once smelled like anything but a Beta. Even before the war. I smell Omega, and that can't be him.”

“According to some classified documents I stumbled across in Shield's oldest databanks,” and she scowled at him for gritting his teeth at her ethical flexibility, “there was actually an underground group in New York City after the Depression that helped Omegas, especially males, who could pass for Beta by looks also pass by smell. They came up with a formula, but it was lost shortly after...the train. Rogers...James Barnes is an Omega, always has been. The Winter Soldier is an Omega who hasn't had a heat since the day you thought you watched him die, and that's because of all the insane chemical shit Hydra had to do to him to make him cryo-viable. And he never let himself have one before he enlisted or during basic, but that part we don't know why or with any certainty how because he's in no mood to tell us. Tony loaned me a self-contained, non-broadcast-enabled AI unit to do a full medical workup on him once we finally got him knocked out. It's not good, Steve.”

“Where...on your scale...is 'not good' this time, Natasha?” The answer he saw first in her eyes rolled his belly. She spoke with that terrible flat tone that only accompanied the ugliest truths her voice would hold—and she could hold back a lot of ugly at need.

“You have two choices if you can get close enough, Steve, since he won't let anyone else we've been able to find near him, including me. Especially me, actually, and until you got here I was the scariest Alpha onsite. He's still brainwashed and has no clue what his body's doing to him. He's more dangerous than I am, and I would fucking know because he was one of my hand-to-hand instructors in my youth. And he's **dying** from Deprivation Disorder. You can try to save him if he'll let you, or you and I can sit together and watch him die before he's out of this heat cycle. Probably before sunset. We're out of other options. And if we call Shield, they'll definitely just shoot him because that would be the easiest solution.”

“Why haven't **you** just shot him?”

"Because _Zima Soldat_ wasn't just a combat teacher, Steve. I am still human in some places. Part of my training was using my body as a means to an end any way it was wanted by a target, and that was the hardest part of the entire regimen for anyone to pass. We trained with many instructors but were tested by only one. To fail meant death, because man or woman in order to pass we had to seduce **him**.” She gestured at the monitor. “When he was in no mood for it. There is a kind of respect there, even if he doesn't remember me from that part of his life. By letting me pass, he showed his kind of respect for any value my life might have, and you know I like my ledgers balanced.” She slowly, too slowly, turned back to the monitor screen, going pale like Rogers had never seen her before.

Barnes was still sprawled gracelessly on the floor where the drugs had dropped him...but now his eyes were open and highly alert. His limbs weren't responding yet, but it was obvious he was wide awake. The time for discussion was over.

“Send me in. But I have one condition.”


	2. Chapter 2

**Summary for the Chapter:**

> Probably not exactly the reunion Steve was hoping for once he'd finally found Bucky again...

Wide awake and fully aware only of his captivity and something being very, very wrong with his body and mind, the Soldier was backed into a corner, nervous and taut and still. The smell in the room made his head reel, all the worse because somehow it was his own smell but totally unfamiliar. Those watching on the small camera mounted above the door saw when he snarled, hunching over the way he'd done periodically the whole time they'd had him. He'd been aware of intermittent cramps in his lower abdomen for days before he'd been trapped, but now each wave was starting to feel like someone had shoved white-hot steel rebar up his ass.

As soon as the attack let up, the door opened to let a tall, graceful man slip into the room. He did not attempt to close in on the Soldier, only watched with an indecipherable expression from just below the camera at the door. “And just who are you?” the Soldier finally snarled. _...The man on the bridge,_ something in his head whispered, and he remembered an older man, hard and ugly blue eyes mismatched to his hypnotic voice, a brutal blow to his face for speaking those remembered words. “I know you.”

“You did. We grew up together in Brooklyn. We were separated during World War Two, when I thought I'd let you die because I couldn't reach you in time. You were...altered to survive cryogenic storage. I was altered for other reasons and by different people, but also ended up frozen until a few years ago.”

“Why are you here? Where am I? What's wrong with me?”

“My name is Steve. Do you remember that?” After a long moment of mental searching, finally a nod. “You've tried to kill me a couple of times now but you didn't know my name then, or when you dragged me out of a river half-dead. Do you remember yours?”

“ _Soldat_. _Zima Soldat_.” Steve winced. More words echoed in the Soldier's head, in Steve's voice this time with hope leaching from his tone at every word: _“Your name is James Buchanan Barnes. I'm not gonna fight you. You're my friend...”_

“Barnes,” he growled hoarsely, and the other man responded strongly; oh, the smell of him was getting nicer and nicer no matter how he reacted. “Sergeant...Barnes. Before I was _Soldat_ , I was a soldier. In a war, a big one. With you, even though I thought you grew up sickly and 4F.”

“Yes, I grew up sickly. The ways I was changed eliminated all those health problems.  You served before I did, but eventually we were both in the 107th and later in the Howling Commandos. You...we...were on a mission together, one of a lot of missions...”

“I fell off the side of a train. Hydra wanted Barnes back...only survivor of the Azzano work...to be retrieved at any cost...”

“That's all correct.” So it was probably true...all the emotional agony Rogers had been put through over thinking his best friend dead had been one spectacularly well-executed trap to get Bucky back in Zola's possession, back to Hydra. The Howlies and those rescued with them in Azzano had made it very clear that Barnes was the only man they'd ever seen again after he'd been chosen to take to that filthy, disgusting parody of a medical laboratory. Several swore they had heard specifically that the Sergeant was the only subject to survive so long by the time Captain America had led them to freedom.

“What's wrong with me?” Another wave of cramps cracked him at last, leaving him sweaty, panting, and pale—though to Steve's relief his pallor was temporary. This time. As one of the country's most desirable Alpha male role models, he considered it a large part of his responsibility to his public image to be educated and well-spoken on many political hot-potato topics, Omega rights and biology included. He did a lot of lectures and such events in the Omega activism communities, and spoke in schools about both primary and secondary gender. In all cases he refused to be paid, insisting that if money be involved it go to one of his few, meticulously-researched favorite charities.

“Do you remember about secondary genders? Alphas, Betas, and Omegas?”

“A little. Enough, probably.”

“Before the war, you hid your secondary gender with a special suppressant. Hydra put so many drugs and who knows what else in your system that they never noticed you weren't the Beta you pretended to be. You're an Omega, and you have something they call Deprivation Disorder. You're in heat, which is part of being an Omega, but since you've never been properly mated by an Alpha, your body's turning on itself, causing Dep Disorder to severely affect your endocrine system. The dysfunction will spread, is already spreading to some of your other bodily systems. You don't have long.” He did not flinch under a long, wary, confused study.

“What...can be done?”

“You have two choices,” Rogers said quietly, sadness gathering around and in his eyes. “You can let an Alpha breed you, or I can break your neck to spare you the suffering that'll take you slowly if you don't get mated pretty much immediately. Biology sure is a bitch.” With a slow sigh, he pulled something small out of a pocket and pressed a button. Above his head, the camera's lens cover slid shut and all its lights went dark. That remote control had been his one condition—he was in the room to either mate or murder the love of his life, and didn't want either possible outcome watched or heard. The Soldier wanted to study his face a moment more, but that didn't work so well when he suddenly doubled over with a bark of pain, dropping to his knees and clutching his belly.

In only a few long strides, Steve was crouched at his side, a hand light on his right shoulder, speaking softly, not making direct eye contact just yet. “That's usually how it ends. The cramps will get strong enough to tear an artery and you'll bleed out inside. It's a cold and lonely death, and there aren't any doctors here capable of saving you if it gets to that point. That's one of the reasons I need you to decide...quickly.”

“What's the other?” the misery-stricken man grated.

“Barnes, I'm an Alpha. Always was, even though I was so sick all the time growing up that I didn't present until one fairly embarrassing weekend leave in Paris with the Howlies but without you well after the serum experiment. If I'm going to save you, that means going into rut—the Alpha version of heat. Consent from either of us stops being a huge priority to me if that happens, and if you don't let me break your neck first I won't be able to make myself after, not unless you convince me you're a threat to my life. And I'm pretty hard to convince.”

“You _want_ to help?”

“I, well, to be honest thinking you were a Beta growing up kept me from a lot of ill-advised thoughts and actions, Buck..” The nickname got him a long look. “Once my mom had me tested and we knew I was the world's least desirable Alpha waiting to happen, I used to **pray** you'd present Omega. And, somehow, want _me_. Throwing myself into a laboratory and then into the war was a great way to distract myself. Oh, shit, time's up,” he grumbled, helping the other man to his feet even as he started backing away, the nearly addictive spicy musk of his Alpha scent starting to get hotter, wilder, more primal. He might be used to the unusual strength of his ruts, but it wasn't normal for them to hit this fast or quite this hard.

The Soldier charged, pinning Rogers to the wall; despite the difference in their builds they were of a height would have massed about the same were it not for the metal arm. For safety's sake Steve's hands were pinned above his head by the prosthetic—not that he was trying to get away.

“Save me and I'll try to find the man you loved,” the Soldier hissed slowly.

“You'll have to let go of my hands, and one of us gets to undo your belt and pants,” Steve growled back, a low boom echoing in the sound that dilated the Soldier's pupils a bit. The Soldier stood frozen a long moment while practicalities were dealt with, and then...the wavering and needy whine in the back of his throat when Rogers ever so gently bit the side of his neck was not what either man expected. The blond took advantage of that distraction, sliding a hand down the back of the other man's pants and, without warning, gently pushing a fingertip through a swollen, irritated opening that should have been slippery and welcoming. Startled and in pain, the Soldier bit him brutally hard on one shoulder, surprised when the reaction that got was Steve moaning and doing...something...with that fingertip, something that chased sparks of agony with a kind of white-hot glory.

“First symptom of Dep Disorder,” Rogers said quietly, working that first ring of impacted slick glands until they felt nearly normal and the Omega was softly groaning at every motion as tears leaked down his broad cheeks, “is usually either impaction or atrophy of slick glands. You're impacted, and just dealing with that might be enough to save you until your next cycle even after we push me into rut, which we will. It's already starting, that's why I backed away, to give you a chance to say no for once in your adult life, to let you make your own choice before biology wrecks **my** brain next. All I can promise is I'll try to listen to you. Is that gonna be enough?”

The answer he got started with a nervous, searching kiss...and as it got more comfortable and then more heated, a quick shove of that intruding finger hit the second row of glands. By the time they were as clear as the first set, Barnes was actively shaking and had bitten Rogers several more times, always surprised when there was no punishment, no stopping, nothing unpleasant but the lingering pain deeper inside.

“Steve,” he half groaned and half growled into the blond's neck, “Oh, God, the way you _smell_...”

“That would be the rut kicking in full strength, and mine's worse than most.”

“Use it, Steve. Save me and see if we can find the man you used to pray for. I want him back.” A deliberate shove from Bucky, jamming the point of his nose directly into the center of where he knew Alphas carried the highest concentrations of scent glands in their neck, undid the other man's worries in a single heartbeat.

“You want me fast, or you want me fun?”

“Fast,” the Soldier groaned, the need in his tone echoed in the musk rolling off the glands in his own neck.

Thirty seconds later, he was pressed face-first to the wall, his pants around his knees, both wrists pressed to the wall in gentle grips, whimpering little moans through the pain of even slow and cautious penetration; Rogers was packing a substantial caliber, so to speak, even for an augmented Alpha. Pain _Zima Soldat_ known so long, so much worse than this, and that threw the moment into a shadow that let him feel his first taste of real pleasure in decades. Whatever Steve had been like before the serum, he forced himself to caution now in his desperation to keep from botching this, to keep from accidentally hurting the love of his sweet young lost life. He didn't have to be rough to be fast, not when the greatest secret of his youth was literally begging for a fast fuck, for salvation...for **him**. Rogers was pretty sure it wasn't just the heat-and-rut hormone combination that made his cock sliding in and out of the other man feel so good, so right, possibly the most real sensation he had understood since his thawing. It was more than enough to get him growling under his breath, sometimes sinking his teeth into Barnes's right shoulder to keep from bellowing outright. And soon enough, he was pretty sure Bucky was learning good things by the truckload. He was convinced by the deep gouges the prosthetic hand drove into the wall as the inevitable climax surged closer and closer for both of them, and the quiet sounds Barnes couldn't restrain inside any longer as they got ever more expressive.

The knot hit quickly, and the lock hurt enough to draw tears from the Omega's eyes—not a surprise, considering it was his first and Steve really could have made a decent living in porn if he'd been bent that way ethically. To his surprise, the Alpha shifted to support his weight in a way that reduced tension on that painful knot. Rogers settled them easily before spending several minutes encouraging the other man to relax, to tuck in against his long frame the way long-ignored instincts were urging, to trust his most primal instincts in this moment.

“You...you feel...so right,” the Soldier managed finally, once the pain was easing and he could start to learn how to enjoy leaning into the Alpha's embrace and slow caresses.

“I never wanted anyone else, Buck, not men or women, whether they chased or asked or just made it obvious. I've never been happier that I took none of those offers.” When he started wiggling, Steve distracted him by working both his long hands on the Omega's sizable erection, leading to almost immediate orgasm. He'd come again twice, moaning and shuddering and further damaging the wall each time, by the time the knot finally slipped. Only once they had their clothes put back together after a surprisingly sweet moment of Omega post-coital submission did Rogers re-activate the camera.

“All right, assholes watching this,” the blond growled. “He's alive, and that means he's mine.”

“You know it's not that simple,” came Natasha's tinny retort.

“It better **get** that simple real fuckin' quick, bitch.”

“Language, Captain,” she tried to joke.

“Fuck you, Nat. I'm going home and I'm taking him with me.”

“That is stupidly, naively dangerous, and you know it.”

“So is trusting you, ever, but that hasn't killed me yet. And I'm not your fucking Captain right now, I'm a rutting Alpha in no mood to let you have a say in this Omega's immediate future. Unlock the fucking door or it comes down if it takes both of us.” Everything about his stance toward the camera spoke of aggression and dislike: his chin tilted down to emphasize his glare, the way he balanced on the front of his feet, the way his arms were held, the stiffness in his spine, all of it screamed that he was taking no opinions or orders this time.

“I...have I ever seen you like this? It seems strange. Unlike you, even if most of my brain doesn't remember you as well as I want to.” Finally, a hint of Bucky slipped in and out of his words.

“It's not my usual comfort zone,” Steve admitted, grateful that the door opened when he tried it. “But when an Omega in heat needs an Alpha, there are things Alphas can't resist. When a friend I have been in love with since the 1930s and thought dead twice over needs me, there are things I won't resist and things I can't. We have a lot to talk about, but I'm not the least bit interested in having that conversation take place in New Jersey.”

Natasha tried to stop them every way she could without resorting to violence, and ended up forced to report failure after Rogers very gently shoved her away from the elevator door, his low growl implying what might happen if anyone dicked around with its controls from outside its doors. Nor could the pair be located once off the base; they'd left with the Harley running dark again, and did not return to Steve's D.C. apartment because they both knew it would be under surveillance. Instead, Rogers aimed them due west as best he could, his stated intent being that they could hide and, if they could keep it quiet, fuck like crazy (at least until their hormones subsided) during the day while riding dark at night. And, being both broke and smart about it, they didn't even try cheap motels. Every day they'd find some way to hide the motorcycle and someplace big enough to hide both of them. Steve recalled volumes of survival training courtesy of the Army, while Bucky remained a crack shot with any weapon and kept them fed by either felling small animals with a sling and a stone or surprising the occasional deer. Luckily, the Soldier had been given extensive knowledge of the American highways to aid in his precision strikes, and he was able to help find isolated places to hide...places where they not only wouldn't be seen or heard but places they wouldn't be smelled either.

Because once the bike was stowed and they were under cover that first day of their flight, the only thing on either mind was sex. This time, Steve declared that fast had worked its magic and it was time to introduce the already-whining Omega to 'fun'. And fun, it turned out, started with a quick litany of memory exercises to re-establish relative identities, hormonal states, and intentions. The next step was Rogers stripping them both, then inviting Barnes to do whatever he wanted. That started with soft kisses and careful nibbles progressing until Steve was enjoying a slow blowjob while curled far enough forward to use two fingertips, this time, on those first two rows of still-impacted slick glands until they'd relaxed enough he could find his old friend's untested prostate.

“Jesus God **Almighty**!” Barnes was on his knees, and his spine was suddenly arched as far backward as it would go inside Steve's long reach, the moment that spot was located. “Alpha,” he quavered when he could actually breathe again, “oh, God, _Steve_...please...I need...I **need**...”

“I know what you need,” Rogers rumbled, rising to his own knees and pulling the other man up to his belly before driving both fingers in deep enough to provoke a scream and a bite. “And I'm pretty sure I know how to make it feel good for both of us. No, love, that does not mean take your teeth out of me...you've got a hell of a mouth on you, Buck, and I **like** it.” He paused, working the painfully swollen slick glands, letting his mouth roam the other man's skin only to pause in one very specific place. “I also know how to try to keep you _mine_ , the kind of mine they can't ever take away, if that's ever what you want.” He oh so lightly drew his teeth across that hyper-sensitized patch of skin, then twisted his head to mix the oils both their neck glands were producing.

“Oh, God...Steve...yes, oh yes...but it would be smarter to talk about bond-bites when I'm not about to start _crying_ for you to knot me.”

“It's gonna be a while,” Rogers warned, baring his teeth only to tip his head back with a moan when his snarl got him bitten again. “I've been saving all the fun everyone thinks I've been having since they thawed me. Never thought I'd get to use it on you, never **wanted** anyone else, gonna make this take _all_...fucking...day...literally.”

It was a very long day, but at the end of it they agreed that staying together was the only choice either man could make no matter how rough the future might get on them. That one day they let themselves live the magic, alternating between naps and fuckery that tended to start with one man asking “Hey, did you ever try...?” or “Did you ever _want_ to try...?”

The next evening, quite a while after another wild-caught meal and Steve having a 'rut brain moment' that involved mounting his lover without much warning, there was an eerie synchronicity in how they simultaneously mounted the motorcycle, the sort of perfect timing and motion that made Rogers's nerves hum pleasantly. He'd read about this charming tattletale phenomenon; scientists described such things as a recently mated pair going through simple actions in smooth unison without prior discussion as 'bond compatibility'. For Bucky to show signs of that so soon could very well mean they were headed for what might be one of the highest BC scores measured, if they were ever willing to be measured.

And as he had quietly prayed since the moment he set the motorcycle rolling that night, the effect only got more frequent as the miles of dark horizon turned to miles of pavement spooling away behind the Harley.


	3. Chapter 3

**Summary for the Chapter:**

> Secrets held far too long turn out to be very important at last.

Four days later they were in the temperate rain forest of the Pacific Northwest, spending the last day they'd need to fucking their way through Barnes's heat. They didn't move along before sleeping that night, opting to build a nice little conifer-branch lean-to for the motorcycle and another for themselves. Both were well concealed enough that they slept the night through, curled up closely together even after it came clear that Bucky's heat was ebbing—because it had also come clear that more of him was Bucky again than the Soldier. Barnes had never admitted to anyone that he'd known damn well he was hopelessly in love with Rogers by the time they were both yet to present a secondary gender at the age of fourteen.

“Those things you said in the room in New Jersey,” the Omega mused quietly over a sparse breakfast that consisted of a couple of rabbits they'd caught near camp and cooked over a tiny fire.

“Every one true, Buck. I don't like to lie, and I absolutely loathe lying to you especially.” Now that nickname got an entirely different response. “I think I was about to turn fifteen when I realized I was done with the world, that my heart had decided it was you or no one.”

“Why didn't you ever tell me?”

“You did the single most impressive job I'd ever seen of concealing a secondary gender. Even your own **parents** thought you were a Beta. I only found out about the special suppressants when Nat called me to come to you in New Jersey.”

“Alphas and Betas have always been allowed to pair off. Not like Omegas used to be banned from one another back then.” Betas could still pair off any way they liked, though most who chose an Omega ended up in a triad with at least a part-time Alpha. Alphas and Omegas were still the most common pairing, and the prejudices about same-primary-gender pairings were fading fast. Alpha with Alpha or Omega with Omega, though, were still looked at askance no matter the primary genders, but at least double Omega pairings weren't still illegal.

“Buck, I loved you like plants love the sun but you know what I was like back then, you know the me that never existed in this century.. Nobody wanted me, not even you, not where I could see it anyway. So I just ignored everyone, stopped trying to date, pulled all my hurt deep inside and tried to turn all that energy into something good.” To his eternal surprise, the former Winter Soldier, among the most feared assassins of the last hundred years, burst into tears.

“I did it for you, Stevie,” he finally managed in a harsh sob. “I had myself tested at one of those private clinics that were always getting burned down, so I knew before I had a chance to present. If I'd let myself present, some bigger, stronger, supposedly _better_ Alpha who was all wrong for me because they weren't **you** would have taken me out of pity because I never looked like what I am. Kept me, most likely indoors constantly because we couldn't have a big burly Omega ruining their delicate and lovely image. I couldn't bear the thought of being trapped into biology with someone who probably would never have even let us be friends because they'd never see past your health and status. And the worst part is I never told you because I _knew_ you'd suggest the two of us, but I didn't think I had a prayer of keeping you safe because back then you know a bigger, meaner Alpha would have **killed** you if they had to in order to weed you out of the gene pool and take me themselves.”

“And what kind of thoughts could you bear about biology now?” That got him a long slow look, in which hints of shimmering beauty rolled in deep and dark places.

“I...keep thinking...just how _pissed_ the Spider would be to see a bond bite on my neck to counter all her fucking demands about my future. I won't tell her how much time I've already spent thinking about how it'd feel to have your teeth in me, how just dizzy stupid happy the last human shred of me is that you actually came for me, chose me, want me now that you're who I **always** saw behind your eyes. The whole world can see what used to be my secret life as the Winter Soldier, and they adore you for trying to stop it and me and Hydra, but it was me you came back for, me you left it all behind for, me you chose to keep. Thinking maybe the most important thing about the world I woke up into this time has been the last week, finding out that whatever's waiting for me out there I honestly want to be yours when I find it, so crucial that I even have a chance to ask this of you, much less get my way. And don't think I haven't noticed the signs of bond compatibility even if I'm pretty sure you saw it first and kept quiet to see if I'd spot it too, you sneaky little punk.”

It didn't always work outside a heat-and-rut combination, but ten minutes later found Rogers sitting with his back to a tree, the only lover he'd ever wanted rocking on his dick, astride his lap back-to-belly and moaning soft pleas when he dropped his head back to rest on the blond's corded shoulder, letting his face turn aside to expose the best spot along the line of scent glands that followed the big tendons framing his wide throat. This wasn't going to take long; Bucky had already discovered the perfect ways to rock and twist his hips, the exact angle that put the most pressure on his prostate to make him see glorious stars no matter how rough they got. The look those stars left echoing across his face, even in profile, would always be enough to just undo Rogers's intentions of self-control. Steve's timing was perfect; the second he felt that one specific spasm that meant he wasn't pulling his knot back out for a while, his teeth sank into the side of Bucky's neck hard and deep. Both of them came, Barnes with a howl he deliberately scaled up to 'it's just a coyote, dear' pitch in case of hikers in hearing range and Steve with a slow ripping groan. The brutal Azzano experiments had been conducted with a weaker version of a serum much like what Rogers had gotten, but even that had come with accelerated healing. It still took over an hour for the bite to stop bleeding, a phenomenon now understood as part of a set of sexual details pointing toward that bond compatibility already so interesting to the military.

The blond was grateful for one thing that wasn't public knowledge: due to some very quiet eugenics programs when he'd been a sickly teen, he'd been surgically sterilized and the serum Stark and Erskine had given him had not reversed that procedure. They'd left him his balls at his mother's insistence, but a large section of _vas deferens_ had been removed between cauterized cutting points. The last thing they needed, bonded or not, was for the still brain-blended former Winter Soldier to turn up pregnant while they were still pretty sure they were being hunted.


	4. Chapter 4

**Summary for the Chapter:**

> Yep, broke the chapter counter again. This is the final chapter, rendering Bond Compatibility a completed work.

Three days further on, Steve sent Natasha's emergency-only phone a request for a face chat of whatever kind both phones would accept. It took her only two minutes to find one and get it uploaded to his burner phone too. “So, where the fuck are you?” she opened, clearly eyeing the background for clues. All she saw was woodland, nothing about it distinctive enough to narrow things down.

“That's none of your concern.”

“You and that shield are still government property, military property, Rogers.”

“The government can have the shield back and good luck finding anyone half as good with it as I ever was. Sam, maybe, and if it's him please tell him I never planned to dump that on him but I'm very sure he'll do great things no matter if he takes it up after me or not. He's a good man, stronger than he thinks. I'm **not** property, Nat, and my service to this country has more than balanced the ledger on what was put into making me Captain America, so that time is over. I'm a human being. So's Bucky, by the way. A human being who deserves to be as free as any other American patriot. A man with a heavy past riding his shoulders, but a weight he's already learning to shed at his own will.” A tilt of his head got Barnes to join him at close enough range that his next comment made perfect sense. “And, as you can see, clearly a bonded Omega now. _My_ Omega as I am _his_ Alpha,” he growled, letting that uniquely Alpha tone creep under his words to match his snarling expression. With his accelerated healing, it had taken the deep marks of teeth only those three days to scar permanently onto Bucky's neck; Barnes gave the screen one silent look before turning to rest his forehead on Steve's heavy shoulder muscles. Rogers gave his former ally a less than friendly smirk when a slow stroke along that sleek brown hair was enough to slide the Omega's eyes shut and shroud his face in a rare kind of peace that was obvious even in profile. Even Romanoff could not hide a flicker of raw astonishment—in that moment, she knew that if anything remained of the _Zima Soldat_ she had first met, it would be gone before long to leave her one of very few alive to recall what training with him had been like. What simply surviving being in the same room with him had once required.

“Good luck trumping biology, Nat. That one even Fury can't pull out his ass this time. And you can tell Shield to ship all my art shit to the Smithsonian exhibit, get rid of everything else, find a good Omega rights charity for my bank account to land with, and rent out that apartment. I'll park the Harley in front of a cop shop so when Shield BOLOs it they won't have too much trouble finding it. I'll leave the shield in a government building somewhere with a note to call you about it. I'm not coming back, Nat. Captain America is a job, a figurehead, something I can't be any more. Now I'm an Alpha with a bonded Omega to care about, just like any other couple other than our various enhancements. I have a life with a worthwhile purpose again, and my mate is that life. I hope you had the good sense to get a shot of those bond scars.” And with that, he closed the call, ripped the electronics out of the phone with unnecessary vigor, and threw the tattered remains onto the coals that had cooked their breakfast.

“So now what?” Bucky wondered, cautiously daring to rest his chin on a broad shoulder, shivering deep when that soft pressure earned him a slow stroke through his hair even when there was no witness needing a point made plain for them. Many miles away, Nat was stonefaced serious when she told her handlers that she had known _Zima Soldat_ better than anyone but his creators, and none of him was left in James Barnes's eyes or expressions.

“Now, us. Whatever we're gonna be. Whoever we are, whoever we can be, and to Hell with whoever we used to be. Wherever we want to go. I am yours, Buck, and I always have been. I just hope knowing you're **mine** because I have always loved you that much is a good thing in your head.”

“The best I can remember,” Barnes answered honestly.


End file.
